Corrugated building sheet



Jan. 14, 1969 v. G. FRANC 3,421,279

CORRUGATED BUILDING swam Filed Oct. 12, 1967 Sheet 1 of 2 2 23' 23' Q U zfla rreooeeo Fu 0 5 a Fu L L L L L L Fig. 2

VICTOR 6. FPA/VC BX @w Mv Y Jan. 14, 1969 v. s. FRANC 3,421,279

,CORRUGATED BUILDING SHEET Filed Oct. 12, 1967 M/VE/V 701?.

VIC 70/? 6. F/PA/VG United States Patent 6 Claims ABSTRACT OF THE DISCLOSURE A corrugated building sheet consisting essentially of flat crests, alternating flat valleys parallel with the crests, and essentially flat sloping webs connecting the crests and valleys and diverging from the crests to the adjacent valleys. At least two of the sloping webs, one on each side of the center of the building sheet is arcuate in crosssection across substantially their entire width.

Cross-references to related applications This is a continuation-in-part of copending application Ser. No. 418,426, filed December 15, 1964, and now abandoned and assigned to the assignee of the present invention.

Background of the invention Field of the invention.This invention concerns an improved corrugated building sheet.

Description of the prior art.The corrugated building sheets with which this invention is concerned are those which have a plurality of relatively flat crests and alternating flat valleys parallel with the crests and having essentially flat sloping webs diverging from the crests to the adjacent valleys. Such corrugated building sheets are shown, for example, in U.S. Patents 1,982,243, 1,936,228, 2,696,281, 2,789,530. Heretofore such corrugated sheets have been available in lengths up to about 12 feet. While warping tendencies were manifested in these prior corrugated building sheets, the adverse effects of those warping tendencies could be overcome because of the relatively short lengths of such sheets.

More recently corrugated building sheets have become available in longer lengths. Sheets of 20 feet, 30 feet, and even 40 feet length are commercially available today. Warping tendencies in these long sheets are irregular and difficult to overcome. Dissimilar warping of successive corrugated building sheets makes it difficult to nest such sheets together for minimum volume packaging. Side-by-side and end-to-end overlapping of warped building sheets is difiicult, and the resulting building wall is frequently unattractive.

The warping tendency in corrugated sheets may arise from a variety of metallurgical reasons, for example, cold-rolled metal sheets usually are thicker in the center than at the edges, a phenomenon known in the metal industry as high crown metal. The crown of the metal.

sheet may be precisely centered or may range for some distance over both sides of the sheet center. However, even metal sheets with no detectable crown present warping tendencies upon corrugation. Metal sheets with nonuniformities, hardness differentials, temper variations, temperature differentials and inequalities resulting from aging phenomena have been advanced as reasons for warping tendencies in corrugated building sheets.

Summary of the invention Without regard to the origin of the warping tendencies, the present invention provides a corrugated building 3,421,279 Patented Jan. 14, 1969 ICC sheet which is substantially free of warping manifestations.

According to the present invention, a pair of the sloping webs of the corrugated building sheet, one web on each side of the center of the sheet, are initially prepared as substantially flat sloping webs similar to all of the other sloping webs of the corrugated sheet. After those two selected ones of the sloping webs have been formed, and before any of the laterally displaced sloping Webs are formed, the two selected ones of the sloping webs are passed between a set of forming rolls to modify the configuration of the two selected sloping Webs from a substantially flat configuration, as formed, to an arcuate configuration. Thereafter the corrugated building sheet is completed according to prior art practices by forming the laterally displaced crests, valleys and sloping webs as required. The resulting corrugated building sheets are essentially free of any manifestations of warping tendencies even in lengths of 40 feet.

Brief description of the drawings The invention will be more fully illustrated and described in the following detailed description by reference to the accompanying drawings in which:

FIGURE 1 is a perspective view of the corrugated building sheet of this invention;

FIGURE 1A is a fragmentary cross-sectional view of a valley, a crest and a connecting sloping web and illustrating changes in the configuration of the sloping web in accordance with the present invention;

FIGURE 2 is a side elevation view of milling apparatus adapted to roll form the present building sheets; and

FIGURES 3, 4, 5, 6-, 7 and 8 are fragmentary crosssection views taken along the lines 33, 44, 5-6, 66, 77 and 88 respectively of FIGURE 2.

Description of the preferred emb0diment(s) Referring to FIGURE 1 there is illustrated a corrugated building sheet 10 having a plurality of crests 11 and alternating valleys 12 which are connected by substantially flat sloping webs 13. Such corrugated building sheets normally terminate with fragmentary sloping webs 14 along each edge. The term crests and the term valleys are relative since frequently these flat surfaces are identical in dimensions, differing only in which set of surfaces (the crests) is closer to the viewer than the other set (the valleys). By reversal of the corrugated sheet, hence, the surfaces become interchanged. The corrugated sheet 10 has four surfaces 11 which have been designated crests and has five surfaces 12 which have been designated valleys. Clearly, if the corrugated sheet 10 were turned over, the five surfaces 12 could be accurately designated crests and the four surfaces 11 could be accurately designated valleys.

A typical metal building sheet has crests 11 and valleys 12 which are 1.625-inches wide and separated by 3.5 inches center-to-center. The plane of the crests is 1.5-inches apart from the plane of the valleys. The overall width of the building sheet is aboutv3l-inches. Such building sheet has 4 crests and 5 valleys, as shown in FIGURE 1. The sloping webs 13 form an angle 44 to 45 with the plane of the crests.

According to this invention, two of the sloping webs 13a, 13b are changed from a substantially flat configuration as formed, to an arcuate configuration in such manner that preferably the arcuate configuration is virtually undetectable visually as a departure from the substantially fiat configuration of the remaining ones of the sloping webs 13. The arcuate sloping webs 13a, 13b

are formed into the corrugated building sheet during its fabrication after the sloping webs 13a, 13b have been fully formed in a substantially fiat configuration and prior to the formation of any succeeding laterally displaced sloping webs 13.

Reference is now directed to FIGURE 1A for a more detailed description of the configurational change produced in the sloping webs of a building sheet in accordance with the present invention.

FIGURE 1A represents a fragment of the building sheet 10, on an enlarged scale, and illustrates a valley 11, a crest 12, the arcuate sloping web 13b and in dotted outline, the sloping web 13b in its initial flat configuration. The flat sloping web 13b is connected to the valley 11 and to the crest 12 by radius corners 15, 16, respectively, in such a manner that the flat sloping web 13b is tangent to the radius corners 15, 16 at points indicated by the dotted arrows T.

When the flat configuration of the flat sloping web 13b is changed to an arcuate configuration, the longitudinal center 17 thereof is displaced through a distance of from one to five metal thicknesses. In FIGURE 1A, for example, the longitudinal center 17 is displaced through a distance of two metal thicknesses.

In accordance with the present invention, it is essential that the change in the web configuration occurs across substantially the entire width of the web 13b as a result of passing through a pair of opposed convex and concave rollers as will hereinafter be described.

The width of the flat sloping web 13b is defined as the distance between the points of tangency T. The thus formed arcuate sloping web 13b is also tangent to the radius corners 15, 16 at points indicated by the arrows T, for example.

It is to be understood the arcuate sloping web 13b is preferably outwardly concave as illustrated in FIGURE 1A. Alternatively, the arcuate sloping web 13b may be inwardly convex. Furthermore, the curvature of the arcuate sloping web 131: preferably corresponds to an arc of a circle.

FIGURE 2 presents a side elevation view of a roll forming line for the assembly of the present corrugated building sheets. A coil 20 of metal sheet 21 is fed to a cutting means 22. Cut-to-length sheets 23 are passed sequentially through rolling stands 3, 4, 8, 5, 6 and 7 to form the present corrugated building sheets 23' which are nested together in a shipping stack 24 after formation. Each of the rolling stands 3, 4, 5, 6, 7 is commonplace in the corrugated building sheet rolling industry. Crosssections through these metal stands are presented in the drawings FIGURES 3, 4, 5, 6 and 7. Throughout the drawings 3, 4, 5, 6, 7 the top rolls are designated by the letter A and the bottom rolls by the letter B. Each of the rolls in any stand is designated further by sequential subscripts from left to right.

As shown in FIGURE 3, the metal sheet 23 passes between rolls 3A (above) and rolls 3B and 3B (below). As a result the metal sheet 23 has formed therein a center crest C and two fiat sloping webs W and W In that condition the sheet 23 passes to the station 4, where, as shown in FIGURE 4, the sheet passes beneath rollers 4A 4A and 4A and above rollers 4B and 4B The roll 4A serves principally to align the sheet 23 whereas the rollers 4A and 4B cooperate to form the valley V and the sloping web W Likewise the rollers 4A and 43 cooperate to form the valley V and web W Additional crests, valleys and sloping webs are introduced into the metal sheet 23 in stations 5, 6 and 7. It will be observed that, in station 7 (FIGURE 7), the rollers 7A and 7B form a crest C and a fragmentary sloping web W Similarly the rollers 7A and 7B form the crest C and the fragmentary sloping web W A corrugated building sheet formed by passage through stations 3, 4, 5, 6 and 7 would conform with prior art practices and would be susceptible to severe warpage, especially in long lengths. The additional forming step of this invention is illustrated in FIGURE 8 wherein a pair of forming rolls 8A and 8A is attached to an upper shaft while a pair of corresponding rolls 8B and 8B is attached to a bottom shaft. The rolls 8A and 8A have a convex configuration whereas the rolls 8B and 813 have a concave configuration. As the metal sheet 23 enters the nip of the rolling stand 8, it has the configuration seen in FIGURE 4, i.e., it contains a crest C two valleys V and V and four substantially fiat sloping webs W W W and W The rolls in rolling station 8 perform work on the sloping webs W and W by changing the form from a substantially fiat sheet to an arcuate, surface identified in FIGURE 8 as SW and SW It will be observed that the lateral portions of the metal sheet 23 (displaced from the arcuate sloping ribs SW and SW are essentially unaltered from the initial flat condition, i.e., the lateral portions have experienced no corrugatng stresses.

It should further be observed that sloping webs W and W have been completely formed as substantially fiat surfaces prior to the conversion of those surfaces to an arcuate configuration SW and SW as shown in FIGURE 8.

It should further be observed that the two arcuate surfaces SW and SW are disposed equidistant from the center crest C i.e., there is one of the arcuate sloping surfaces on each lateral half of the finished corrugated building sheet. In the event extremely wide corrugated building sheets are manufactured, it may be desirable to provide more than two of the arcuate sloping surfaces in the sheet. The two arcuate surfaces SW and SW illustrated in FIGURE 8 correspond to the arcuate webs 13a and 13b of the finished building sheet as shown in FIG- URE 1. In FIGURE 8, the sloping surfaces SW and SW laterally adjoin the central valleys V and V Further, those two sloping surfaces SW and SW are formed from initially substantially fiat sloping webs W and W which were converging, i.e., which were nonparallel.

I claim:

1. An improvement in a corrugated metal building sheet made by roll forming and consisting essentially of plural flat crests and alternating plural flat valleys parallel with said crests and having essentially flat sloping webs diverging from each of said valleys to the adjacent ones of the said crests,

said improvement comprising alterations in selected ones of said sloping webs, said selected ones comprising at least two and less than all of the said sloping webs and further comprising one of the said selected ones being on each side of the center of the said building sheet, said alterations comprising an arcuate cross-section across substantially the entire width of each of said selected ones, said selected ones of said flat webs being formed from sloping webs which are initially essentially flat.

2. The improvement of claim 1 wherein there are two selected ones of said sloping webs and the said selected ones are webs which extend from the outer edges of two different ones of said crests laterally toward the nearest side of the said building sheet.

3. The improvement of claim 1 wherein the curvature of each of said selected ones of said sloping webs corresponds to an arc of a circle.

4. The improvement of claim 1 wherein said selected ones of said sloping webs are outwardly concave.

5. The improvement of claim 1 wherein the longitudinal centers of the said selected ones of said sloping webs are displaced from that position occupied by the longitudinal centers when the said selected ones of said sloping webs were essentially fiat sloping webs, through a distance in the range of from one to five metal thicknesses.

5 6. The improvement of claim 1 wherein each of said selected ones of said sloping webs is connected to the adjacent valley and the adjacent crest by radius corners, each of said selected ones of said sloping Webs being tangent to both of said radius corners.

References Cited UNITED STATES PATENTS 308,826 12/1884 Butz 52-630 6 1,470,835 10/1923 Hathaway 52-453 XR 3,059,733 10/1962 Hermann 52-630 3,150,465 9/1964 Johnson 52-537 3,228,162 1/1966 Gregoire 52-536 X FRANK L. ABBOTT, Primary Examiner.

PRICE C. FAW, ]R., Assistant Examiner.

US. Cl. X.R.

7/1902 Bailey 52-450 10 29-180 

